46 percent of the area) since the 2003 report (fig. 4-2a). Of
particular note are the Appalachian Mountains; the Mississippi
alluvial plains; the northern temperate prairies; the cold deserts
of the central intermountain West; and the Cascade Mountains
of the Pacific Northwest. Those regions, where the number of
forest bird species have continued to decline or have changed to
a decreasing trend (34 ecoregions comprising 47 percent of the
area) since the 2003 report (fig. 4-2b), are prominent throughout the semiarid prairies of the Great Plains; the plateau region
west of the Appalachian Mountains; coastal areas in New
England, Texas, and the Pacific Northwest; and the regions that
comprise the intensive agricultural lands in the upper Midwest.
Why can’t the entire indicator be reported at
this time?
Monitoring the count of different species over large geographic
areas is difficult. For this reason, we lack systematic inventories
that permit the estimation of species numbers for many groups
(e.g., nonvascular plants, insects, and fungi). The increase in
the number of forest-associated species reported here reflects
growing inventory coverage among groups for which our
understanding of habitat associations has been incomplete
(e.g., vascular plants, and invertebrates). Until comprehensive
biodiversity inventories are implemented, trends in the number
of native forest species will have to be interpreted cautiously.
The most fundamental need is to develop monitoring programs
that are economically feasible and applicable across the diverse
groups of species that inhabit forest ecosystems.
Indicator 1.05. Number and Status of
Native Forest-Associated Species at Risk,
as Determined by Legislation or Scientific
Assessment
What is this indicator and why is it important?
This indicator provides information on the number and status
of forest-associated species at risk or in serious decline. It
accomplishes this by monitoring the number of native species
that have been identified by conservation science or mandate
to be at risk of global extinction. As the number of species
considered to be rare increases, the likelihood of species extinction also increases. Demographic and environmental events
such as failure to find a mate, disease, disturbance, habitat
loss, and climate change interact to increase extinction risk as
populations become smaller. Because important ecosystem
functions (e.g., productivity, nutrient cycling, or resilience)
can be degraded with the loss of species, concern exists that
the goods and services humans derive from ecological systems
will become diminished as more species become rare. For this
reason, tracking the number and percent of at-risk species is a
measure of the health of forest ecosystems and their ability to
support species diversity.
What does the indicator show?
Among forest-associated species (vascular plants, vertebrates,
and select invertebrates), 77 (less than 1 percent) were
Figure 4-2. A comparison of the 2003 report trends (1975–1999) to recent trends (1999–2006) in forest bird species
counts. (a) Those strata that have continued to see increases in bird species counts or were declining in the 2003
report but have become increasing. (b) Those strata that have continued to see decreases in bird species counts or
were increasing in the 2003 report but have become decreasing (data provided by U.S. Geological Survey).
(a)
(b)
Change in forest
bird species
Became increasing
Still increasing
National Report on Sustainable Forests—2010
Change in forest
bird species
Became increasing
Still increasing
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determined to be presumed or possibly extinct, 4,005 (27
percent) were determined to be at-risk of extinction (includes
species that are critically imperiled, imperiled, or vulnerable
to extinction), and 10,576 (71 percent) were determined to be
apparently secure. The percentage of forest-associated species
in each conservation status category varies by taxonomic group
(fig. 5-1a). The number of possibly extinct and at-risk species
is proportionately greatest among select invertebrates (32 percent), followed by vascular plants (28 percent), and vertebrates
(16 percent). Within forest-associated vertebrates, the greatest
proportion of possibly extinct and at-risk species is found among
amphibians (34 percent). Birds (14 percent), freshwater fishes
(12 percent), mammals (11 percent), and reptiles (11 percent)
show proportionately lower numbers of species that are of
conservation concern. At-risk species that are associated with
forest habitats are concentrated geographically in Hawaii, the
arid montane habitats of the Southwest, chaparral and sage
habitats of Mediterranean California, and in the coastal and
inland forests of northern and central California (fig. 5-1b).
What has changed since 2003?
Since the 2003 report, a broader accounting of species that
inhabit forests has resulted in an increase in the number of species
that are considered possibly extinct or at risk of extinction, with
the greatest increase reported among vascular plants (3,644
more species). The number of species of conservation concern
also increased among select invertebrates (108 more species)
and vertebrates (23 more species). The sizable percentage
gains among vascular plants and invertebrates (fig. 5-2a) are
largely attributable to newly available data rather than from
a real increase in the percentage of species consider at risk.
Among the relatively well-studied vertebrates, an increase of
about 0.8 percent has occurred since the 2003 report. Among
vertebrate species groups (fig. 5-2b) the greatest percent gains
in species thought extinct or at risk of extinction were observed
among amphibians (an increase of 2.2 percent), followed by
mammals (an increase of 1.0 percent), reptiles (an increase of
0.9 percent), and birds (an increase of 0.5 percent).
Why can’t the entire indicator be reported at
this time?
Information on the conservation status of obscure species is
lacking in many cases. Among all species (not just forest associated), 281 (1.7 percent) vascular plant, 14 (less than 1 percent)
vertebrate, and 660 (9.0 percent) invertebrate species (select
groups) have not been, as yet, assigned a conservation status
category nor a habitat affinity. Given the number of species
for which conservation status ranks are forthcoming, trends in
the number of forest-associated species by conservation status
will need cautious interpretation because gains are expected
as unranked species are evaluated. Regional trend analyses
were also limited by the fact that the ecoregional stratification
changed from the 2003 to the 2010 reports.
Figure 5-1. (a) The percent of vascular plant, vertebrate, and invertebrate species associated with forest habitats
determined to be possibly extinct, at risk of extinction, secure, or unranked. (b) The percentage of forest-associated
species (vascular plants, vertebrates, and select invertebrates) occurring in each ecoregion determined to be at risk
of extinction (does not include species classified as possibly extinct). (2009, data provided by NatureServe.)
(a)
(b)
100
Percent of species
80
60
40
20
0
Vascular
plants
Unranked
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Secure
Vertebrates
At-risk
Invertebrates
Possibly extinct
Percent
0–1.6
>1.6–3.3
>3.3–8.8
>8.8–12.3
>12.3–66.5
National Report on Sustainable Forests—2010
Figure 5-2. A comparison of the percent of forest-associated species that have been determined possibly extinct or
at risk of extinction between the 2003 and 2010 reports among (a) vascular plants, vertebrates, and select invertebrates, and (b) among the relatively well-known mammal, bird, reptile, amphibian, and freshwater fish species groups.
Because the conservation status of forest-associated freshwater fish species (▲) were unavailable for the 2003
report, only a single-point estimate for the 2010 report is shown. (Actual reporting dates were 2002 and 2009.)
35
35
(b)
30
30
25
25
Percent of species
Percent of species
(a)
20
15
20
15
10
10
5
5
Vascular plants
Vertebrates
Invertebrates
0
Mammals
Birds
Reptiles
Amphibians
Fishes
0
2003 report
2010 report
Indicator 1.06. Status of Onsite and Offsite
Efforts Focused on Conservation
of Species Diversity
What is the indicator and why is it important?
This indicator provides information that describes onsite
and offsite efforts to conserve species diversity. Onsite
conservation efforts are those implemented within the forest.
Offsite conservation efforts are usually measures of last resort
which may move a species from its natural habitat or range to
specially protected areas or into captivity as part of a breeding
program or collection.
Some forest species and habitats may have declined to such
an extent that intervention is required to safeguard them for
the future. As a result of the biological diversity losses caused
by human pressure, different sectors of society (governments,
nongovernmental organizations (NGOs), and individual
citizens) are increasingly involved in conservation measures.
These conservation initiatives include scientific studies about
species at risk, keystone species assessments, laws, and projects
that reinforce conservation of biological diversity, forest
restoration, and connectivity.
It is more practical to estimate expenditures associated with
efforts to conserve biological diversity than to directly measure
the results of those efforts. Expenditures by public agencies
directed at conservation of biological diversity fall into four
National Report on Sustainable Forests—2010
2003 report
2010 report
broad categories: (1) research associated with biological diversity,
including among others, knowledge about keystone species,
threatened species, functional groups, and spatial distribution;
(2) environmental education and information about the importance of biological diversity, and (3) conservation projects
related to habitat restoration and biological diversity management. A fourth category of this indicator is (4) the proportion
of forest area managed for biological diversity conservation,
outside of protected areas, relative to total forest area. This
indicator is closely related to Indicators 1.02 and 1.09.
What does the indicator show?
Federal expenditures for research, education, and management
associated with conservation of forest biological diversity are
concentrated in five Federal agencies:
1.Forest Service
2.National Park Service
3.Bureau of Land Management
4.U.S. Fish and Wildlife Service
5.U.S. Geological Survey
In combination, those agencies spent approximately $2 billion
in 2008 on research, education, and management that fosters
conservation of forest biological diversity (fig. 6-1). These
expenditures are the equivalent of $2.68 for every acre of forest
land in the United States State natural resource agencies and
hundreds of NGOs make additional expenditures associated
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